[Openmcl-devel] Questions about Cocoa app development

Didier Verna didier at lrde.epita.fr
Thu Jan 24 04:10:08 PST 2008


I'm interested in developing some Cocoa/GUI applications in CL, and it
seems to me that CCL is the best tool for that right now. So I tried it
for the first time and went through the Currency Converter tutorial. I
must admit I was quite puzzled by the simplicity of delivering a Mac
application !!

I have some general questions and also some about the tutorial itself:

1/ How can you develop a GUI application interactively, or at least have
a GUI application combined with a listener so that you can inspect
things during development ?

2/ How do you execute specific Lisp code when the application starts,
both before and after the GUI is setup ?

And about the tutorial itself:

1/ I don't quite understand the point in having an instance of the
converter class visible at the Cocoa layer. The way I see it (correct me
if I'm wrong), I want the Lisp layer to perform the actual work, and
the Cocoa layer only to display stuff and to get input. So the
converter-controller should be the only interface between the two

Hypothesis: having the controller visible down below, as an outlet in
the converter-controller class, lets the cocoa layer instanciate it at
the right time, and avoids the need for a global variable to access it
from the controller's methods ??

2/ In the same vein, why having the actual work, ie the convertCurrency
method defined in the Objc layer at all ? This sort of defeats the whole
point of having CL on top of it: now it's here to define the classes,
but performs no real job at all.

Which brings me to the last, more general question:

if I want to perform the work in CL (here: to the math on single-float
CL values), I'd have to go between CL and Objc types. How do you do that

Thank you very much !

Resistance is futile. You will be jazzimilated.

Didier Verna, didier at lrde.epita.fr, http://www.lrde.epita.fr/~didier

EPITA / LRDE, 14-16 rue Voltaire   Tel.+33 (0)1 44 08 01 85
94276 Le Kremlin-Bicêtre, France   Fax.+33 (0)1 53 14 59 22  didier at xemacs.org

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